Pipetting apparatus for aspirating and dispensing liquids

Abstract

A pipetting apparatus for aspirating and dispensing liquids having a pipetting unit with an interchangeable vessel that receives a liquid to be transferred, a holder for the pipetting unit, a positioning device for the pipetting unit, a micrometering unit, and an electronic control device. The micrometering unit is embodied separately from the pipetting unit and has a separate electronic control unit. The pipetting unit has a coupling device and the micrometering unit has a counterpart coupling device that matches the coupling device for the purpose of coupling. Coupling device and/or counterpart coupling device is/are switchable. The holder or the micrometering unit has a contact device with at least one electrical contact element and the micrometering unit or the holder has a counterpart contact device, matching the contact device, with at least one counterpart electrical contact element for making electrical contact with the contact element.

What is claimed is: 
     
       1. A pipetting apparatus comprising:
 a pipetting unit, 
 a pipetting vessel detachably mountable on the pipetting unit at a coupling point for receiving a liquid from a storage vessel and dispensing the liquid into a receiving vessel, 
 a displacement unit arranged in the pipetting unit for taking up of liquid from the storage vessel and for dispensing the liquid from the pipetting vessel, 
 a holder to which the pipetting unit is mounted, the holder being mounted for movement, 
 a positioning device connected to the holder for moving the pipetting unit in conjunction with the holder, 
 a micrometering unit located on a platform and to which the holder is detachably connectable in a precisely defined relative position, and 
 an electronic control device having transmission means for electronically providing control commands, power supply and data between the electronic control device and individual components of the pipetting apparatus, 
 an electronic control unit for the micrometering unit, the electronic control unit being separate from said electronic control device, 
 wherein the holder has a coupling device and the micrometering unit has a counterpart coupling device that matches the coupling device for coupling of the pipetting unit, via the holder, to the micrometering unit, and 
 wherein at least one of the coupling device and the counterpart coupling device is switchable between a coupled position and a decoupled position for coupling the micrometering unit to the pipetting unit and uncoupling the micrometering unit from the pipetting unit, 
 wherein one of the holder or the micrometering unit has a contact device with at least one electrical contact element, 
 wherein the other of micrometering unit or the holder has a counterpart contact device, matching the contact device, the counterpart contact device being provided with at least one counterpart electrical contact element for making electrical contact with the contact element, 
 wherein the contact elements of the contact device are arranged so as to be movable between a contact position and a disconnected position due to movement of the coupling device, and 
 wherein when said contact elements are in the contact position, said electrical control unit of micrometering unit is electrically connected to the transmission means of electronic control device and wherein electrical contact electrically connects the micrometering unit to the electronic control device. 
 
     
     
       2. The pipetting apparatus as claimed in  claim 1 , wherein a switching device is provided on the micrometering unit or on the holder, said switching device controlling switching between said coupled position and said decoupled position. 
     
     
       3. The pipetting apparatus as claimed in  claim 2 , wherein the switching device has a movable locking bolt, said locking bolt cooperating with the contact device on the holder. 
     
     
       4. The pipetting apparatus as claimed in  claim 1 , wherein the coupling device and the counterpart coupling device are movable relative to one another in a joining direction in order to electrically couple the micrometering unit to the pipetting unit. 
     
     
       5. The pipetting apparatus as claimed in  claim 1 , wherein the micrometering unit has an actuating device for a back and forth movement causing liquid contained in the vessel to be dispensed from the vessel. 
     
     
       6. The pipetting apparatus as claimed in  claim 5 , comprising a switching device operatively connected to the actuating device of the micrometering unit. 
     
     
       7. The pipetting apparatus as claimed in  claim 6 , comprising a drive unit for at least one of the switching device and the actuating device, wherein the control unit of the micrometering unit is connected for control purposes to the drive unit. 
     
     
       8. The pipetting apparatus as claimed in  claim 7 , wherein at least one of the actuating device or the drive unit are controllable by the control unit of the micrometering unit. 
     
     
       9. The pipetting apparatus as claimed in  claim 1 , wherein the at least one contact element is a spring-mounted contact pin, or inherently resilient contact finger. 
     
     
       10. The pipetting apparatus as claimed in  claim 1 , wherein the at least one counterpart contact element has a contact face that makes electrical contact with the at least one contact element. 
     
     
       11. The pipetting apparatus as claimed in  claim 1 , wherein an actuator is provided on the holder or the micrometering unit, said actuator being connected to the control device of the pipetting apparatus for control purposes and to the contact device for drive purposes. 
     
     
       12. The pipetting apparatus as claimed in  claim 11 , wherein at least one electrical contact element of the contact device is movable away from the counterpart contact device up to a travel limit by the actuator before the micrometering device is coupled to the pipetting unit, and is movable toward the counterpart contact device during or after the coupling of the micrometering unit to the pipetting unit, such that the at least one contact element then comes into engagement with the at least one counterpart contact element so as to make electrical contact. 
     
     
       13. The pipetting apparatus as claimed in  claim 1 , wherein the micrometering unit coupled to the pipetting unit is movable together with the pipetting unit into spatially different operating positions by means of the positioning device.